Github Workflow WITH authorization check.

gh-workflow-auth-example.yml

name: "Full Job Example"

on:
  workflow_dispatch:
    inputs:
      version:
        description: Version (See Releases)
        required: true

jobs:
  setup:
    name: SETUP
    runs-on: ubuntu-latest
    outputs:
      REPOSITORY: ${{ steps.setup.outputs.REPOSITORY }}
      FUNCTION: ${{ steps.setup.outputs.FUNCTION }}
      ZIPFILE: ${{ steps.setup.outputs.ZIPFILE }}
    steps:
    - name: Setup
      id: setup
      run: |
        REPOSITORY=${PWD##*/}
        echo "::set-output name=REPOSITORY::$(echo $REPOSITORY)"
        FUNCTION=$(cut -d- -f2 <<< ${PWD##*/})
        echo "::set-output name=FUNCTION::$(echo $FUNCTION)"
        ZIPFILE="${FUNCTION}.${{ github.event.inputs.version }}.zip"
        echo "::set-output name=ZIPFILE::$(echo $ZIPFILE)"
  authorization:
    name: AUTHORIZATION
    needs: setup
    runs-on: ubuntu-latest
    steps:
    - name: Authorization
      id: authorization
      if: |
        github.actor == 'AlexAtkinson' ||
        github.actor == 'user2' ||
        github.actor == 'user3'
      run: |
        echo "::set-output name=AUTHORIZED::true"
    - name: UNAUTHORIZED
      if: ${{ steps.authorization.outputs.AUTHORIZED != 'true' }}
      run: |
        echo "${{ github.actor }}, you are not authorized to run this job!"
        exit 1
  work:
    name: WORK
    needs: [authorization,setup]
    runs-on: ubuntu-latest
    steps:
    - name: Work
      run: |
        echo FUNCTION: ${{ needs.setup.outputs.FUNCTION }}
        echo VERSION: ${{ github.event.inputs.version }}
  work-notice:
    name: JOB NOTICE
    needs: [work,setup]
    runs-on: ubuntu-latest
    steps:
    - name: "Slack Notification"
      uses: "rtCamp/action-slack-notify@v2"
      env:
        SLACK_CHANNEL: ${{ secrets.SLACK_CHANNEL }}
        SLACK_COLOR: ${{ needs.work.result }} # or a specific color like 'good' or '#ff00ff'
        SLACK_ICON_EMOJI: ":hal9000:"
        SLACK_TITLE: "DEPLOY NOTICE"
        SLACK_MESSAGE: "Environment: TEST\nTester: ${{ needs.setup.outputs.FUNCTION }} ${{ github.event.inputs.version }}"
        SLACK_USERNAME: DevOps_Bot
        SLACK_WEBHOOK: ${{ secrets.DEVOPS_SLACK_WEBHOOK }}
  auth-notice:
    name: UNAUTHORIZED NOTICE
    if: failure()
    needs: [authorization,setup]
    runs-on: ubuntu-latest
    steps:
    - name: "Slack Notification"
      uses: "rtCamp/action-slack-notify@v2"
      env:
        SLACK_CHANNEL: ${{ secrets.SLACK_CHANNEL }}
        SLACK_COLOR: failure
        SLACK_ICON_EMOJI: ":hal9000:"
        SLACK_TITLE: ":wave: UNAUTHORIZED DEPLOY ATTEMPT"
        SLACK_MESSAGE: "Environment: TEST\nTester: ${{ needs.setup.outputs.FUNCTION }} ${{ github.event.inputs.version }}"
        SLACK_USERNAME: DevOps_Bot
        SLACK_WEBHOOK: ${{ secrets.DEVOPS_SLACK_WEBHOOK }}

Can a adjust this logic easily enough to use a secret with a list of users, rather than embedding it in a workflow if.

A possibly better way would be to query GitHub team memberships. But the management of the team memberships would have to be suitably restricted and logged.